Glycans and glycoconjugates are widespread in nature and play pivotal roles in cell-cell recognition, cell differentiation, and immunological responses. Most glycans and glycosylation reactions require nucleotide sugars as their essential building blocks. Therefore, the commercial availability of nucleotide sugars will determine future opportunities for carbohydrate-based innovations, just as the availability of nucleotides was a prerequisite for today?s $6.1 billion PCR market of DNA-based technologies. Due to glycoscience?s reliance on nucleotide sugars, there is an urgent need for a production pipeline to provide these essential reagents. The goal of our ?Chemo-enzymatic synthesis of nucleotide sugar libraries and therapy-relevant derivatives? Fast-Track project is to meet this need and commercialize a stable, affordable and diverse supply of nucleotide sugars to drive advances in glycoscience. It is our long-term objective to bring 11 nucleotide sugars, 26 nucleotide derivatives, and the associated processes to market. In Phase I Aim 1, we will enzymatically synthesize GDP-L-Fuc, GDP-Man, CMP-Neu5Ac, CMP-Neu5Gc, and 7 UDP sugars: Glc, Gal, GlcNAc, GalNAc, GlcA, GalA, and Xyl. In Aim 2, we will create optimized in situ generation systems for the UDP-, GDP-, and CMP-sugars to be coupled with transferase reactions. Our methods will utilize de novo or salvage pathway enzymes and be scaled up to 1 gram production reactions. In Phase II Aim 1, we will chemically modify the nucleotide sugars to form 26 new derivatives containing azido, fluoride, deoxy or methoxy functional groups at various positions on CMP-Neu5Ac, GDP-L-Fuc, and UDP-GlcNAc/GalNAc. In Aim 2, we will further optimize all 37 production platforms for commercialization. Our methods will combine chemical synthesis with de novo and salvage pathway enzyme reactions to produce the most efficient products. The health relevance of this project is linked to developments in glycan technology, due the fundamental nature of nucleotide sugars as building blocks for glycoconjugates and polysaccharides. A stable supply of nucleotide sugars and their derivatives will facilitate experiments that advance our understanding of cell surface markers, cell recognition, and protein-carbohydrate interactions. In turn, this cell specific information has the potential to impact individualized medicine, drug-delivery, and cell targeting therapies.